Almost half the workers in Verizon Communications' (New York) wireline telecommunications business went on strike on Sunday as negotiations for a new labor contract failed.

The strike, involving 45,000 workers, is the first walk-out that Verizon, one of the two big U.S. telephone network operators, has faced since 2000, when about 80,000 workers went on strike for about three weeks.

Verizon and two unions -- The Communications Workers of America (CWA) and the International Brotherhood of Electrical Workers (IBEW) -- had been in talks since late June but were still far apart when their contract expired Saturday night.

The workers who went on strike are technicians and customer support employees in the wireline unit, which provides traditional phone services to homes and businesses in the Northeast as well as high-speed Internet and FiOS television service.

The two sides were unable to agree on issues related to healthcare contributions, pension plans and work rules, according to Verizon and the CWA.

Verizon is looking to keep costs in check at its wireline business, which has been declining for a decade as customers have disconnected their home phones in favor of cellphone and Internet services.

A representative for the CWA, which represents about 35,000 of the workers, said bargaining talks were expected to resume on Sunday while employees were told to start picketing as early as 6 a.m. EDT outside their work locations.

"A strike is a hardship for all and not to be undertaken lightly," said Jim Spellane, an IBEW spokesman. "I think that the fact that we are on strike instead of finalizing an agreement is a testimony to Verizon's intransigence throughout the process."

Michael Paleski, an employee of Verizon for 23 years, was among the roughly 250 people gathered in front of Verizon's Manhattan corporate headquarters.

"Nobody here wants a strike. I'm sure nobody on the other side wants a strike either. But we're also very disappointed that the company put forward so many demands for givebacks. We feel that's really the sticking point for us," Paleski said.

On Monday morning, thousands of striking workers joined mass picket lines and rallied at over 100 Verizon work locations across New York and New Jersey to pressure the company to back off its demands, said the CWA.

Among the changes it is seeking, Verizon said it wants to freeze employee pension plans and replace them with an enhanced 401(k) plan. It also wants workers to contribute to healthcare insurance premiums.

The CWA says the contributions to healthcare that Verizon wants the union members to make were unacceptable, and that increases in deductibles would make the proposed healthcare plan unaffordable.

It said the profitable company is asking for far too many concessions from affected workers, who include technical and customer service employees in Verizon's wireline business.

Verizon has 93,000 workers in its wireline business, of whom 58,000 are unionized. Including its Verizon Wireless venture with Vodafone Group Plc, the company's total workforce is 196,000 employees.